Algae are known to be used as fertilizer, as food, and as a pollution control in sewer plants. Recently, their ability to produce more biomass per unit area in a year than any other form of biomass has increased interest in algae as a renewable energy source. Cultivating algae for this purpose usually involves algae species that can produce algae oil and requires closed containers, a tightly controlled environment, and sophisticated process technology. Chlorella, a genus of single-celled green algae, has been used for fuel production. The presence of other algae, especially fast growing hair algae, is undesirable in such algae fuel plants.
Some algae, e.g. those of the Cladophora, have been used in fire retardant building material known in German as “Algilit”. “Algilit” is known to having been used in western Siberia for many years. Algal plastics which comprise a foamed and stabilized filamentous algal fiber matrix having substantial dimensional stability are disclosed in U.S. Pat. No. 5,779,960.
Carbon dioxide is considered a green house gas, increasing concentration of which in the earth's atmosphere leads to a rise in global temperature levels, an effect often referred to as global warming. A reduction in carbon dioxide emissions is deemed desirable. Ideally, the concentration of carbon dioxide in the atmosphere would be kept constant or even reduced, by permanently withdrawing carbon dioxide from the atmosphere at the same or at a faster rate than carbon dioxide is emitted into the atmosphere. However, reducing or eliminating the emission of carbon dioxide that is generated by fossil fuel power plants such as coal, oil or gas power plants, has proven to be difficult, inefficient, and expensive. The ability to reduce carbon dioxide emissions is however of particular interest in jurisdictions that regulate carbon dioxide emissions, including taxing such emissions, for example by requiring an emitter to purchase carbon dioxide emission rights.
One approach to reducing carbon dioxide emissions from fossil fuel power plants is to pump carbon dioxide that is generated in power plants into underground storage, e.g. caverns or retired mines. However, this approach is expensive and potentially dangerous, if carbon dioxide escapes from its underground storage.
Another approach is to switch power generation plants from fossil fuels to renewable fuels, thereby reducing the dependency on coal, oil and gas as energy sources. However, renewable energy sources from crop compete with crop needed as food, are inefficient, and can at best case be carbon neutral. Burning renewable energy typically emits about the same amount of carbon dioxide that the underlying crop has withdrawn from the atmosphere during its growth. A reduction of the carbon dioxide in the atmosphere is not possible.